68 ideas
20121 | Grammar only reveals popular metaphysics [Nietzsche] |
24082 | Is the will to truth the desire to avoid deception? [Nietzsche] |
15945 | Second-order set theory just adds a version of Replacement that quantifies over functions [Lavine] |
15914 | An 'upper bound' is the greatest member of a subset; there may be several of these, so there is a 'least' one [Lavine] |
15921 | Collections of things can't be too big, but collections by a rule seem unlimited in size [Lavine] |
15937 | Those who reject infinite collections also want to reject the Axiom of Choice [Lavine] |
15936 | The Power Set is just the collection of functions from one collection to another [Lavine] |
15899 | Replacement was immediately accepted, despite having very few implications [Lavine] |
15930 | Foundation says descending chains are of finite length, blocking circularity, or ungrounded sets [Lavine] |
15920 | Pure collections of things obey Choice, but collections defined by a rule may not [Lavine] |
15898 | The controversy was not about the Axiom of Choice, but about functions as arbitrary, or given by rules [Lavine] |
15919 | The 'logical' notion of class has some kind of definition or rule to characterise the class [Lavine] |
15900 | The iterative conception of set wasn't suggested until 1947 [Lavine] |
15931 | The iterative conception needs the Axiom of Infinity, to show how far we can iterate [Lavine] |
15932 | The iterative conception doesn't unify the axioms, and has had little impact on mathematical proofs [Lavine] |
15933 | Limitation of Size: if it's the same size as a set, it's a set; it uses Replacement [Lavine] |
15913 | A collection is 'well-ordered' if there is a least element, and all of its successors can be identified [Lavine] |
15926 | Second-order logic presupposes a set of relations already fixed by the first-order domain [Lavine] |
15934 | Mathematical proof by contradiction needs the law of excluded middle [Lavine] |
15907 | Mathematics is nowadays (thanks to set theory) regarded as the study of structure, not of quantity [Lavine] |
15942 | Every rational number, unlike every natural number, is divisible by some other number [Lavine] |
15922 | For the real numbers to form a set, we need the Continuum Hypothesis to be true [Lavine] |
18250 | Cauchy gave a necessary condition for the convergence of a sequence [Lavine] |
15904 | The two sides of the Cut are, roughly, the bounding commensurable ratios [Lavine] |
15912 | Counting results in well-ordering, and well-ordering makes counting possible [Lavine] |
15949 | The theory of infinity must rest on our inability to distinguish between very large sizes [Lavine] |
15947 | The infinite is extrapolation from the experience of indefinitely large size [Lavine] |
15940 | The intuitionist endorses only the potential infinite [Lavine] |
15909 | 'Aleph-0' is cardinality of the naturals, 'aleph-1' the next cardinal, 'aleph-ω' the ω-th cardinal [Lavine] |
15915 | Ordinals are basic to Cantor's transfinite, to count the sets [Lavine] |
15917 | Paradox: the class of all ordinals is well-ordered, so must have an ordinal as type - giving a bigger ordinal [Lavine] |
15918 | Paradox: there is no largest cardinal, but the class of everything seems to be the largest [Lavine] |
15929 | Set theory will found all of mathematics - except for the notion of proof [Lavine] |
15935 | Modern mathematics works up to isomorphism, and doesn't care what things 'really are' [Lavine] |
15928 | Intuitionism rejects set-theory to found mathematics [Lavine] |
20360 | We Germans value becoming and development more highly than mere being of what 'is' [Nietzsche] |
24077 | Necessity is thought to require an event, but is only an after-effect of the event [Nietzsche] |
20126 | The strength of knowledge is not its truth, but its entrenchment in our culture [Nietzsche] |
20119 | We became increasingly conscious of our sense impressions in order to communicate them [Nietzsche] |
20122 | We have no organ for knowledge or truth; we only 'know' what is useful to the human herd [Nietzsche] |
4423 | We assume causes, geometry, motion, bodies etc to live, but they haven't been proved [Nietzsche] |
6579 | Nietzsche's perspectivism says our worldview depends on our personality [Nietzsche, by Fogelin] |
24083 | It would be absurd to say we are only permitted our own single perspective [Nietzsche] |
20115 | All of our normal mental life could be conducted without consciousness [Nietzsche] |
20117 | Only the need for communication has led to consciousness developing [Nietzsche] |
20118 | Only our conscious thought is verbal, and this shows the origin of consciousness [Nietzsche] |
20116 | Most of our lives, even the important parts, take place outside of consciousness [Nietzsche] |
20120 | Whatever moves into consciousness becomes thereby much more superficial [Nietzsche] |
2932 | 'Know thyself' is impossible and ridiculous [Nietzsche] |
24078 | Thoughts cannot be fully reproduced in words [Nietzsche] |
24081 | Most of our intellectual activity is unconscious [Nietzsche] |
2933 | Why do you listen to the voice of your conscience? [Nietzsche] |
20141 | Higher human beings see and hear far more than others, and do it more thoughtfully [Nietzsche] |
24076 | A morality ranks human drives and actions, for the sake of the herd, and subordinating individuals [Nietzsche] |
22471 | Nietzsche thought it 'childish' to say morality isn't binding because it varies between cultures [Nietzsche, by Foot] |
2935 | No two actions are the same [Nietzsche] |
20198 | Many virtues are harmful traps, but that is why other people praise them [Nietzsche] |
4275 | You cannot advocate joyful wisdom while rejecting pity, because the two are complementary [Scruton on Nietzsche] |
2934 | To see one's own judgement as a universal law is selfish [Nietzsche] |
24080 | We should give style to our character - by applying an artistic plan to its strengths and weaknesses [Nietzsche] |
20125 | The ethical teacher exists to give purpose to what happens necessarily and without purpose [Nietzsche] |
9306 | To ward off boredom at any cost is vulgar [Nietzsche] |
24079 | The best life is the dangerous life [Nietzsche] |
2936 | Imagine if before each of your actions you had to accept repeating the action over and over again [Nietzsche] |
6842 | Nietzsche says facing up to the eternal return of meaninglessness is the response to nihilism [Nietzsche, by Critchley] |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
2931 | God is dead, and we have killed him [Nietzsche] |